ASTM D3387-1983(2003) Standard Test Method for Compaction and Shear Properties of Bituminous Mixtures by Means of the U S Corps of Engineers Gyratory Testing Machine (GTM)《用美国工程兵团回.pdf

1、Designation: D 3387 83 (Reapproved 2003)Standard Test Method forCompaction and Shear Properties of Bituminous Mixturesby Means of the U.S. Corps of Engineers Gyratory TestingMachine (GTM)1This standard is issued under the fixed designation D 3387; the number immediately following the designation ind

2、icates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers two separate mod

3、es of opera-tion of the Gyratory Testing Machine (GTM), namely: (1)GTM fixed roller mode; and (2) GTM oil-filled roller mode.The fixed roller mode of operation is employed in testing forcompaction and strain indices only, while the oil-filled rollermode of operation is employed in testing for streng

4、th proper-ties as well as compaction and strain indices. This test methodis for use with mixtures containing asphalt cement, asphaltcut-back, asphalt emulsion, or tar and aggregate up to 1 in.(25.4 mm) maximum size in the 4-in. (101.6-mm) diameterspecimen and 1.5 in. (38.1 mm) maximum size in the 6-

5、in.(152.4-mm) diameter specimen.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitati

6、ons prior to use.2. Referenced Documents2.1 ASTM Standards:C 136 Test Method for Sieve Analysis of Fine and CoarseAggregates2C 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials23. Terminology3.1 Definitions:3.1.1 gyrographa recording of shear strain

7、experiencedby the bituminous mixture during the compaction test (see Fig.1).3.1.2 gyratory anglea measure of the magnitude of thegyratory strain. Three pertinent angles are defined as follows:3.1.2.1 Initial gyratory angle or shear strain (machine set-ting) uo(see Fig. 1),3.1.2.2 Minimum gyratory an

8、gle or shear strain (minimumgyrograph band width) ui(see Fig. 1), and3.1.2.3 Maximum gyratory angle or shear strain (maximumgyrograph band width) umax(see Fig. 1).3.1.3 gyratory stability index (GSI)the ratio of the maxi-mum gyratory angle to the minimum gyratory angle (see Fig.1).3.1.4 gyratory com

9、pactibility index (GCI)the ratio of theunit mass (total mix) at 30 revolutions of the GTM to the unitmass (total mix) at 60 revolutions of the GTM.3.1.5 gyratory shear strength (SG)the shear resistance ofthe specimen which is, among other things, a function of theimposed vertical pressure and degree

10、 of strain (see Annex A1).3.1.6 gyratory shear factor (GSF)the ratio of the mea-sured gyratory shear strength to the approximate theoreticalmaximum induced shear stress, that is, a factor of safety typeindex with regard to failure in simple shear for the definedloading conditions.4. Significance and

11、 Use4.1 Either mode of operation (fixed roller or oil-filled roller)is intended to be used for guidance in selection of the optimumbitumen content and establishing unit mass requirements;additionally the oil-filled roller mode of operation is intendedfor use in arriving at a shear strength factor (r

12、eferred to asgyratory strength factor, GSF) with regard to shear under theload and strain conditions selected for the test. The proceduredescribed here is for one selected degree of shear strain (in thiscase an initial gyratory angle of 1) and some selected verticalpressure (in this case the anticip

13、ated tire contact pressure).Attention is called to the fact that the gyratory angle selectedshould relate to the anticipated pavement deflection. The 1angle selected here should have wide application but should thepavement engineer select a different shear angle (such as adegree of shear strain), it

14、 should be so indicated in the report.It is essential that the vertical pressure correspond to themaximum anticipated tire contact pressure, since the theoreti-cal stress for compaction and maximum induced shear used indetermining the compaction requirements and the gyratorystrength factor (GSF) is

15、based on the concept of employingrealistic loads for the test.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.26 onFundamental/Mechanistic Tests.Current edition approved July 10, 2003. Published Septem

16、ber 2003. Originallyapproved in 1974. Last previous edition approved in 1998 as D 3387 83 (1996).2Annual Book of ASTM Standards, Vol 04.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.FIG. 1 GTM Compaction and Shear TestD 3387 83

17、(2003)24.2 The gyratory strength factor (GSF) must be interpretedwith due recognition of the use of the somewhat arbitrarilyselected degree of strain and the assumption of plane maximumshear (the unit contact pressure divided by p) for a strip loadon a homogeneous elastically isotropic mass.4.3 The

18、use of this method for guidance in the selection ofthe optimum bitumen content is limited to mixtures that aresusceptible to the development of excess pore pressure whenthe voids become overfilled with bitumen. (This restrictiondoes not apply to the gyratory strength factor, GSF.)Agyratorystability

19、index (GSI), in excess of unity, indicates a progressiveincrease in plasticity during densification. An increase in thisindex indicates an excessive bitumen content for the compac-tion pressure employed and foretells instability of the bitumi-nous mixture for the loading employed.Areduction in oil-f

20、illedroller pressure during the compaction process likewise indi-cates loss of stability because of overfilled voids; this phenom-enon also serves as an indicator of maximum allowablebitumen content as does the widening of the gyrograph whichgives a stability index in excess of unity.4.4 The gyrator

21、y compactibility index (GCI) is an indicatorof the compactibility of the mix. The closer this indexapproaches unity, the easier the mix is to compact.5. Apparatus5.1 Gyratory Testing Machine (GTM) and AppurtenancesThe primary equipment for this test is the Gyratory TestingMachine (GTM)3and appurtena

22、nces. Fig. 2 is an assemblydrawing of the machine (and appurtenant equipment) indicat-ing essential features, including the wall friction apparatus anda schematic of the gyrating mechanism. The fixed upper rollerand the oil-filled upper roller are interchangeable; the rollerbeing selected to fit the

23、 mode of operation of the GTM.5.2 OvensVentilated ovens shall be provided for heatingaggregates, bituminous material, and specimen molds and forcuring cut-back mixes and emulsion mixes. It is recommendedthat the heating units be thermostatically controlled so as tomaintain the required temperature w

24、ithin 5F (2.8C).5.3 Balances, one having a capacity of 5 kg or more,sensitive to 1.0 g; and one having a capacity of 2 kg, sensitiveto 0.1 g.3A novel mechanization of the original Texas gyratory principle. This machineis manufactured by Engineering Developments Co., Inc. of Vicksburg, MI 39180,under

25、 letters Patent Nos. 2972249 and 3478572.FIG. 2 Gyratory Testing MachineD 3387 83 (2003)35.4 ThermometersArmored glass or dial-type thermom-eters with metal stems are recommended. A range from 50 to400F (9.9 to 20.4C) with sensitivity of 5F (2.8C) isrequired.5.5 Spacer Blocks, two metal spacer block

26、s for use inzeroing the specimen height measuring equipment. These shallall be of 2-in. (50.8-mm) diameter with one each of thefollowing lengths: 2.50 6 0.005 in. (63.50 6 0.013 mm) and3.75 6 0.005 in. (95.25 6 0.013 mm).5.6 Miscellaneous ApparatusTrowels, spatulas, scoops,gloves, rubber gloves, met

27、al pans, 4-in. (101.6-mm) diameterpaper disks, and 6-in. (152.4-mm) diameter paper disks.6. Test Specimens6.1 Selection of Bitumen Content for SpecimensConductlaboratory tests for one specimen each at a minimum of threebitumen contents, one above, one below, and one at theestimated optimum content (

28、see Note 1). The incrementalchange of bitumen content should generally be 0.5 %. Forextremely critical mixes, lower the incremental change ofbitumen content to 0.3 % and for highly absorptive aggregates,increase the incremental change of bitumen content to 1.0 %.Tests on additional bitumen contents

29、should be conducted asnecessary when check tests are needed.6.2 Preparation of AggregatesIn accordance with TestMethod C 136, obtain a sieve analysis on the fine and coarseaggregate (aggregate shall be separated by means of a No. 4(4.75-mm) sieve). Separate the aggregate into the various sizefractio

30、ns necessary for accurately recombining into test mix-tures conforming to specified grading requirements.6.3 Preparation of MixturesCombine the moisture-freeaggregates into batches sufficiently large to make specimensapproximately 2.50 in. (63.5 mm) long in the 4-in. (101.6-mm)diameter mold and 3.75

31、 in. (95.3 mm) long in the 6-in.(152.4-mm) diameter mold. For normal aggregates, this willrequire approximately 1200 g for the 4-in. (101.6-mm) diam-eter specimens and approximately 4050 g for the 6-in. (152.4-mm) diameter specimens. Heat the aggregate to the propermixing temperature; then weigh the

32、 required amount of bitu-men at the proper temperature into the aggregate mixture.Mixing of the aggregate and bitumen shall be as thorough andrapid as possible; mechanical mixing is recommended.NOTE 1A first approximation of the optimum amount of bitumen forthe aggregate may be determined by any met

33、hod commonly employed bythe laboratory. A method that has been found suitable in some laboratoriesis the centerfuge kerosene equivalent method.46.3.1 For mixes employing penetration/viscosity grades ofasphalt, the temperature of the aggregate and asphalt at the4California Highways and Public Works,

34、Vol 20, No. 7, July 1942, pp. 14-17.FIG. 3 GTM Shear TestD 3387 83 (2003)4time of mixing should correspond to the temperatures antici-pated to be used at the plant during manufacture of the pavingmix. These temperatures will generally be somewhere in therange of 250 to 325F (121 to 149C). Once the m

35、ixingtemperature is selected, it should be so controlled that theviscosity of the bitumen will not vary more than 650 cStduring the mixing process.6.3.2 For tar mixtures, the temperature of the aggregate andtar at the time of mixing should correspond to the temperaturesto be used at the plant during

36、 manufacture of the paving mix.This temperature will generally not exceed 225F (107C).Once the mixing temperature is specified, it should be socontrolled that the viscosity of the tar will not vary more than65 Engler specific viscosity during the mixing process.6.3.3 For mixtures employing liquid as

37、phalts (cut backs oremulsions), the asphalt need not be heated but the aggregateshould be dried to constant weight at 221 to 230F (105 to110C). The liquid asphalt should be combined with theaggregate at room temperature. Following mixing, cure theloose mixture in a ventilated oven maintained at 221

38、to 230F(105 to 110C) for at least 12 h prior to compaction at thistemperature. The mix may be stirred occasionally duringcuring to accelerate loss of volatiles.6.4 Size of SpecimensThe 4-in. (101.6-mm) diameterspecimens shall be approximately 2.50 in. (63.5 mm) long. The6-in. (152.4-mm) diameter spe

39、cimens shall be approximately3.75 in. (95.3 mm) long.7. Calibration7.1 See Annex A2.8. Procedure8.1 GeneralThe GTM-fixed roller is employed when thecompaction test only is required. The GTM oil-filled roller isemployed when both the compaction test and the shear test arerequired. The oil-filled roll

40、er procedure is accomplished insequential steps including the compaction test, shear test, andwall friction test as outlined in this section. (The procedure fordetermining the machine correction for SGis presented inAnnex A2.) When using the fixed roller, inapplicable portionsof the following instru

41、ctions are ignored.8.2 Compaction or Compaction and Shear TestFig. 1 andFig. 3 illustrate data sheets which are suitable for recording andcalculating compaction or compaction and shear test resultsand for displaying the gyrograph (shear strain) recording. Thegyratory strain angles uo, ui, and umaxar

42、e indicated on thegyrograph displayed in Fig. 1. For this test, set the initialgyratory angle, uo, at 1. Roller positions 2 and 4 (Fig. 1) areused in setting the initial gyratory angle, uo.Atrial batch of mixis used in making the initial gyratory angle adjustment. MakeFIG. 4 Compaction and Shear Pro

43、perties vs. Bitumen ContentD 3387 83 (2003)5certain that the specimen molds are thoroughly clean and freeof defects. Excessive wear or grooving in the molds in the areaof contact with the upper and lower plates will have an adverseeffect upon the compaction as well as the gyrograph (shearstrain) rec

44、ording. Instructions for the compaction temperaturesfor the laboratory specimens are presented in 6.3.1 through6.3.3. Set the GTM heater at 140F (60C) at least 15 minbefore starting the compaction test. Preheat the mold and baseplate at 140F (60C). Place paper disks in the bottom of themold and on t

45、op of the loose mix to prevent the bitumen fromadhering to the end plates. Place the entire batch in the moldavoiding hand troweling or tamping as it is desired that thecompaction process be completely mechanically controlled inorder to attain the highest degree of precision and reproduc-ibility. Us

46、e the mold-carrying tray to load the mold containingthe mixture into the machine having first placed the wallfriction yoke in position when employing the oil-filled rollermode of operation. Raise the ram and use a vertical pressurejust sufficient to retain the specimen while the front of the moldchu

47、ck is tightened securely in position. When the mold chuckis securely tightened, increase the vertical pressure to the fullcompaction test pressure. Now bring the gyrograph recorderpin into contact and actuate the roller carriage and continueuntil 29 revolutions have been applied.At the completion of

48、 29revolutions, stop the carriage and record the specimen heightand roller pressure readings (when required) at three positions1, 3, and 4 (29 to 30 revolutions), as indicated in Fig. 1, thuscompleting 30 revolutions. Continue to apply additional revo-lutions until a total of 59 is reached. Again re

49、cord height androller pressure readings (when required) at three positions 1, 3,and 4 (59 to 60 revolutions) as indicated in Fig. 1, thuscompleting 60 revolutions. (Specimen height and roller-pressure reading may be taken at more frequent intervals ofrevolutions when more detailed delineation of these parametersis desired.)8.3 Wall Friction Test (applicable when employing oil-filled roller mode of operation)Immediately following thecompaction and shear test, lower the vertical ram slightly so asto relieve the pressure on the bottom roller. L